I particularly don't like the shutter lock and sometimes the shutter jammed on the R3A. Half of the time, I'm actually forgot to turn the lock off before shooting, some users may find this handy but i found this to be an extra annoying thing. On the R3A in AE mode, the shutter locked up sometimes, I wasn't unable to released the shutter or winded the film at all and yes, the len cap was not on or camera was focus in dark area either. When the film is loaded, the rewind crank of R3M has more resistance, robust and it doesn't feel as loose as the R3A. Beside those points the cameras are pretty much identical and ACE!...oohhh my R3A was a victim of salt water and rusted to the shutter blades, that's why I bought a new r3m